Multi-Chassis—Link Aggregation Group (MC-LAG or MLAG) is a type of a Link Aggregation Group (LAG) in which the constituent ports terminate on separate chassis. MC-LAG is primarily used for providing redundancy for cases in which one of the chassis fails. Implementations of MC-LAG may be based on the LAG standard, which is specified, for example, in “IEEE 802.1AX-2008—IEEE Standard for Local and metropolitan area networks—Link Aggregation,” Nov. 3, 2008. The standard IEEE 802.1aq, 2012, titled “Shortest Path Bridging,” provides alternative specifications to the MC-LAG.
Methods for handling a MC-LAG are known in the art. For example, U.S. Patent Application Publication 2012/0314715 describes systems and methods for implementing a multi-chassis link aggregation group (MLAG) in a network. This may be achieved by connecting at least two switches to a plurality of servers, with at least one logical bridging device and at least one MLAG configured in between the network and the plurality of servers. The at least one logical bridging device may be associated with the at least one MLAG. The system may include at least one MLAG per logical bridging device, but may include more MLAGs than logical bridging devices.
U.S. Pat. No. 8,032,653 describes a method for allocating bandwidth in a network appliance that includes a plurality of guaranteed bandwidth buckets used to evaluate when to pass traffic through the network appliance. The method includes providing a shared bandwidth bucket associated with a plurality of the guaranteed bandwidth buckets, allocating bandwidth to the shared bandwidth bucket based on the underutilization of bandwidth in the plurality of guaranteed bandwidth buckets and sharing excess bandwidth developed from the underutilization of the guaranteed bandwidth allocated to the individual guaranteed bandwidth buckets.
U.S. Patent Application Publication 2006/0133279 describes a hierarchical multi-rate multi-precedence policer that discards packets based on assigned precedence levels. When traffic exceeds an available service rate, the policer drops packets of lower precedence levels to make room for packets of higher precedence levels. In certain implementations, the policer also guarantees bandwidth to each level, thus preventing complete loss of lower precedence traffic when there is a large amount of higher precedence traffic.